v0.9.0

Added

• Added the Gqdit data-structure with all the proper documentation and
  examples for all its methods
• Added a new table to the readme/top-level module docs for describing all
  the different data-structures in the crate for comparison with one
  another
• Added another method to InclusiveInterval, contains_interval()

Changed

• Renamed contains_entire_interval() methods to contains_interval() to match
  InclusiveInterval::contains_interval()
• Renamed InclusiveInterval::contains() to
  InclusiveInterval::contains_point() to match the new
  InclusiveInterval::contains_interval() method
• serde's Serialize and Deserialize implementations are now optional via a
  "serde" feature which is documented in the features section of the
  readme/top-level module docs